The PSD/CDS coalition (Portuguese: Coligação PSD/CDS, PPD/PSD.CDS-PP) is a recurring conservative^[3] political and electoral alliance in Portugal formed by the Social Democratic Party (PPD/PSD) and CDS – People's Party (CDS-PP).

Though the history of coaltion between the two parties stretches back over 40 years, the parties have not run together in most elections and, when they did so, they always retained their own autonomous parliamentary groups afterwards.

PSD and CDS were founded after the 1974 Revolution that overthrew the Estado Novo dictatorship.

Both parties have had a close affinity for the most part of their existence. Previous to any electoral alliance, they both endorsed the same presidential candidate in the first democratic presidential election of 1976, Ramalho Eanes, who also had the backing of the Socialist Party.

The first time the two parties were together in a coalition was in the general and local elections of 1979, under the Democratic Alliance banner, albeit along with the People's Monarchist Party and the Reformers [pt], a small group of Socialist Party dissidents. This first continuous coalition lasted until 1983 and run a total of two general elections (1979 and 1980) and two local elections (1979 and 1982). Both parties endorsed again a single candidate in the 1980 and 1986 presidential elections.

In Portugal, presidential elections aren't formally partisan, although all major parties usually endorse a candidate from their ranks. In the 1991 presidential elections, PSD backed former Socialist Prime Minister Mário Soares, while CDS endorsed its own former minister Basílio Horta. Since 1996, both parties have always endorsed the same candidate (former PSD Prime Minister Aníbal Cavaco Silva in 1996, 2006 and 2011, and former PSD ministers Joaquim Ferreira do Amaral in 2001and Marcelo Rebelo de Sousa in 2016 and 2021). The candidates supported by PSD and CDS have won since 2006.

The coalition with just the two parties appeared formally for the first time in the 1997 local elections and, at the local level, it has been expanded to more municipalities in each following election till today (2001, 2005, 2009, 2013, 2017 and 2021), holding, as of 2021, 31 mayors out of 308 municipalities in the country.

The coalition was on the ballot in the 2004 Azores regional election, as Coalition Azores (Portuguese: Coligação Açores, CA), but failed to win that election. The coalition was also on the ballot in the 2023 Madeira regional election, as We are Madeira (Portuguese: Somos Madeira, SM). The coalition has been on the ballot in two European Parliament elections, 2004 as Forward Portugal (Portuguese: Força Portugal, FP), and 2014 as Portugal Alliance (Portuguese: Aliança Portugal, AP).

On elections for the Assembly of the Republic, the two-party coalition was only tried once, in the 2015 legislative election, as Portugal Ahead (Portuguese: Portugal à Frente, PàF), and it polled ahead with almost 39% of the votes, but was unable to remain in power as it didn't gain enough seats for a majority.

Both parties are running again along with PPM as the Democratic Alliance for the 2024 European and general elections, except in Madeira's constituency in the general, where only PSD and CDS are running together as First Madeira.

• Democratic Alliance (Coalition PSD/CDS/PPM)